In customary sewing machines the needle rod and the sewing foot, as well as the thread pulling lever, if applicable, are driven from a common shaft whose rotary movement in each case is converted by a crank or an eccentric drive into a linear back and forth movement of the needle rod and of the sewing foot. This has not only the disadvantage that relatively many individual parts are required and relatively large masses have to be moved, but also that the movement phases of the needle rod and of the sewing foot within a cycle of operation cannot be practically changed. The stroke of the rod is as a rule changeable to a limited degree through an adjustment of the eccentric, but for the adjustment of the stroke the sewing drive has to be interrupted.
From DE 198 27 846 A1 an industrial sewing machine is already known in which the needle rod is linearly moved back and forth by means of an electromagnetic linear motor. By corresponding control of the electromagnets arranged along the needle rod path the needle rod can be moved according to a determined speed or acceleration profile. Along with the considerable expense for the control of the plurality of electromagners, the solution raises above all the disadvantage that the precision of the end positions of the needle rod stroke required for forming a quality stitching can only be obtained with very slow working speeds. Moreover, the drive principle is applicable only for straight line movements and can therefore not without problems be transferred to other kinds of movement, such as for example the rotary movement of a rotating hook.